#36 Use API constant instead of hard coded header name

Signed-off-by: Sven Strittmatter <sven.strittmatter@iteratec.com>

Author: Weltraumschaf

src/main/java/io/securecodebox/persistence/defectdojo/service/ImportScanService.java

@@ -58,7 +58,7 @@ public ImportScanService(final @NonNull DefectDojoConfig config) {
      */
     private HttpHeaders getDefectDojoAuthorizationHeaders() {
         HttpHeaders headers = new HttpHeaders();
-        headers.set("Authorization", "Token " + defectDojoApiKey);
+        headers.set(HttpHeaders.AUTHORIZATION, "Token " + defectDojoApiKey);
         return headers;
     }